1. Field of the Invention
The present invention relates to a traction control device for a vehicle, including a slip-state detecting means for detecting an excessive slipping of a driven wheel of the vehicle, and a driven wheel torque control means for calculating an initial control torque of an engine in accordance with the acceleration of the vehicle to provide a torque in accordance with said initial control torque to the driven wheel, when the excessive slipping of the driven wheel is detected by the slip-state detecting means.
2. Description of the Prior Art
Such traction control device for the vehicle is disclosed in Japanese Patent Application Laid-open No.258933/91 proposed by the present applicant.
When the vehicle including the above prior art traction control device is fallen into an excessive slipping state during traveling on an upward sloping road, it is more difficult to accelerate the vehicle, as compared with the traveling on a flat road. Therefore, when the vehicle is traveling on such an upward sloping road, a friction coefficient of a road surface is misjudged to be small, notwithstanding that the actual friction coefficient of the road surface is relatively high. As a result, the initial control torque of the engine in operating the traction control device is suppressed to a value smaller than an appropriate value and hence, a sufficient acceleration may not be obtained.